Over $6000 to install TTI headers on 66 Barracuda

If no one else has mentioned it, I'd consider paying an attorney $100 to write a letter explaining that the charges are "well in excess" of normal, and ask that a standard diagnostic fee (or something similar) be charged in exchange for the release of the car.

Also, you could suggest a mediator or arbitrator.

Either way, you're likely to get out for a LOT less than 6 grand with no work being done.

X 2

I had this happen to me years ago. I had an accident in my Mach I and brought it to the local Ford garage in the small town I lived in. I was young and the owner figured I would be naive. He collected Mustangs and new I had a couple. He quoted me 2,500 for the body work and gave me a written itemized quote. About 1/2 through he told me they went over budget and I owed him almost 5,000 dollars and to fully finish it would cost a couple more. I said I didn't have that much money. He said I would have to give him my other cars along with the Mach I to pay him for the work done or I had to cough up the money. As a 19 year old he knew he had me. I said to heck with it and stopped by a lawyer to get his view. 50 dollars later, a letter was sent to the Ford Garage. I paid the guy 10% over estimate for ONLY the work completed. I think in the end it cost me a hair over a $1,000. I took the car elsewhere and had it completed. Don't let this guy rip you off.